Arm64: Better addressing mode for array access whose elements are accessed byref #67981
Description
Continuing on #64819, we should also improve the array accesses if the element is accessed using ref.
private int[] _srcData = new int[20];
public int[] Test(int m, int n, byte v)
{
for (int i = 0; i < n; i++) {
Consume(ref _srcData[i]);
}
return _srcData;
}G_M11249_IG03:
mov x0, x19
ldr x0, [x0,#8]
ldr w1, [x0,#8]
cmp w21, w1
bhs G_M11249_IG06
add x0, x0, #16
ubfiz x1, x21, #2, #32
add x1, x0, x1 ; <-- can compact with previous instruction?
mov x0, x19
movz x2, #0xd1ffab1e
movk x2, #0xd1ffab1e LSL #16
movk x2, #0xd1ffab1e LSL #32
ldr x2, [x2]
blr x2
add w21, w21, #1
cmp w21, w20
blt G_M11249_IG03Without ref:
private int[] _srcData = new int[20];
public int[] Test(int m, int n, byte v)
{
for (int i = 0; i < n; i++) {
Consume(_srcData[i]);
}
return _srcData;
}G_M11249_IG03:
mov x0, x19
ldr x0, [x0,#8]
ldr w1, [x0,#8]
cmp w21, w1
bhs G_M11249_IG06
add x0, x0, #16
ldr w1, [x0, w21, UXTW #2] ; <-- compacted
mov x0, x19
movz x2, #0xd1ffab1e
movk x2, #0xd1ffab1e LSL #16
movk x2, #0xd1ffab1e LSL #32
ldr x2, [x2]
blr x2
add w21, w21, #1
cmp w21, w20
blt G_M11249_IG03